JPH0433361A - Hybrid integrated circuit device - Google Patents

Abstract

PURPOSE:To prevent a switching noise from flowing from the insulated metal board of a hybrid integrated circuit device into the chassis of an electronic apparatus by a method wherein an active filter having a circuit structure in which a reactor is connected between the output terminal of a rectifying circuit and a switching device is mounted on the insulated metal board. CONSTITUTION:An active filter is composed of a bridge rectifying circuit composed of diodes D1-D4, a reactor L whose one terminal is connected to the positive DC output terminal of the bridge rectifying circuit, a transistor Q0 whose collector and emitter are connected between the other terminal of the reactor L and a ground respectively, a damper diode D5 whose anode is connected to the collector of the transistor Q0 a smoothing capacitor Cd which is connected between the cathode of the damper diode D5 and the ground and a control circuit COM which supplies a control pulse phi to the base of the transistor Q0. Therefore, both in the positive half cycle and in the negative half cycle of commercial AC, the reactor L is always inserted into the collector side of the transistor Q0 so that the emitter potential of the transistor Q0 can be always the ground potential stably.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention relates to a hybrid integrated circuit device in which a power active filter is mounted on an insulated metal substrate, and in particular, it relates to a hybrid integrated circuit device in which a power active filter is mounted on an insulated metal substrate. The present invention relates to a hybrid integrated circuit device equipped with an active filter that suppresses leakage current to the circuit.

(b) Prior art In recent years, active filters have been attracting attention from the standpoint of noise countermeasures for rectified power supplies. - A detailed active filter will be explained with reference to FIG.

The active filter includes a bridge rectifier circuit consisting of diodes D1 to D4, a reactor connected between the current input terminal of this bridge rectifier circuit and a commercial AC power supply indicated by a voltage V66, and a pair of DC output terminals of the bridge rectifier circuit. The circuit consists of a transistor Q connected in parallel between them, a capacitor C1 for smoothing the DC output of the bridge rectifier circuit, and a damper diode D5 connected between the DC output terminal of the bridge rectifier circuit and the smoothing capacitor C6. Note that normally 1.5KH2 is used to control the operation of transistor Q.
A control circuit that outputs a control pulse φ having the above frequency is omitted.

Next, the operation of this active filter will be explained.

In the half-cycle when the commercial AC current actor L side is positive,
While the transistor Q is turned on by the high-level control pulse φ, the reactor and diode DI) transistor Q
- Diode D4 forms a closed circuit and current flows through the reactor, and during the half cycle when the reactor side of commercial AC is negative, while transistor Q is on, diode D2 - transistor Q - diode D3 - reactor flows. A closed circuit is formed, and a current similarly flows through the reactor L. Then, when the control pulse φ becomes low level and the transistor Q is turned off, the previous two closed circuits are opened and a back electromotive force is generated in the reactor. Since this back electromotive force is in the same phase as the commercial alternating current, while the transistor Q is turned off, the voltage obtained by adding the back electromotive force of the reactor L and the voltage of the commercial alternating current is applied to the bridge rectifier circuit, and this rectification pressure is increased. The damper diode F D s is forward biased and the smoothing capacitor C1 is charged.

Conventionally, this active filter was composed of discrete components, but the wiring between each discrete component became long, and the inductance component of the wiring induced new switching noise. For this reason,
It became necessary to house the active filter within a large shield structure, and the demand for downsizing of power supplies could not be met satisfactorily.

Therefore, the present inventor filed a patent application for a hybrid integrated circuit device in which this active filter was mounted on an insulated metal substrate.
This hybrid integrated circuit device will be described with reference to FIG.

That is, both surfaces of a metal substrate (40) made of aluminum or the like are coated with an insulating oxide film (42) formed by anodizing, and on one of the insulating oxide films (42), an insulating resin layer (46) of epoxy or the like is formed. A copper foil circuit pattern (48) is formed through the copper foil. Then, on this circuit pattern (48), the diodes D, -D4 and D5, the transistor Q, and further circuit parts constituting the control circuit are surface-mounted in the form of a chip, thereby realizing an extremely small active filter.

Furthermore, as is clear from Fig. 7, the circuit pattern (48
), the ground pattern is connected to the metal substrate under the insulating oxide film (42) with a bonding wire (54) for the purpose of removing stray capacitance caused by the insulating oxide film (42) and insulating resin layer (46). There is.

When such a hybrid integrated circuit device is incorporated into an electronic device, it is usually mounted in a structure with good heat dissipation by bringing the insulating oxide film (42) on the back surface of the metal substrate (40) into contact with the chassis. Therefore, in this structure, the stray capacitance C, (see Figure 8) with at least the insulating oxide film (42) as a dielectric between the metal substrate (40) and the chassis of the electronic device is
Occurs throughout the area.

(c) Problems to be Solved by the Invention However, in the hybrid integrated circuit device described above, the emitter potential of transistor Q of the active filter fluctuates greatly at high frequencies, which leaks as noise into the chassis of the electronic device via the insulated metal substrate. There are particular problems due to the use of an insulated metal substrate.

The cause of this problem will be explained with reference to FIGS. 8(A) and 8(B).

FIG. 8(A) shows an equivalent circuit of the hybrid integrated circuit device in a half cycle in which the reactor L side of commercial AC is positive. In the positive half cycle, a closed circuit is formed by reactor L - diode D, - transistor Q - diode D4,
Reactor L is positioned to serve as a collector load for transistor Q.

On the other hand, FIG. 8(B) shows an equivalent circuit of the hybrid integrated circuit device in a half-cycle in which the commercial AC current actor L side is negative. In the negative half cycle, a closed circuit is formed by diode D2-transistor Q-diode D3-reactor, and reactor L becomes the emitter load of transistor Q.

As is clear from this, the positive half period (Figure 8 (A))
Then, the collector potential of the transistor Q changes so as to switch between the charging voltage of the smoothing capacitor C4 and the ground potential at the frequency of the control pulse φ. Note that the emitter potential is maintained at the ground potential. However, the negative half period (
In FIG. 8(B)), since the reactor L serves as the emitter load of the transistor Q, the emitter potential controls the voltage between the charging voltage of the smoothing capacitor C7 and the ground potential. 11) <Rusφ
It changes so that it switches at the frequency of .

Since the ground pattern of the hybrid integrated circuit device and the aluminum substrate (40) are connected by the bonding wire (54), in the negative half cycle, the potential of the aluminum substrate (40) is equal to the charging voltage of the smoothing capacitor C6. and the ground potential at the frequency of the control pulse φ.

The C leaks out as switching noise to the chassis of the electronic device via a stray capacitance C2 formed between the aluminum substrate (40) and the chassis of the electronic device.

(d) Means for Solving the Problems The present invention has been made in view of these problems, and includes an active filter having a circuit configuration in which a reactor is connected between the pressure end of a rectifier circuit and a switching element on an insulated metal substrate. By doing so, it is possible to realize a hybrid integrated circuit device that greatly improves the problems of the conventional technology.

(e) The active filter has a circuit configuration in which a reactor is connected to the DC output end of the working rectifier circuit, and the other end of the reactor is intermittently grounded by a switching element, so the active filter is made into a hybrid integrated circuit device. The reactor acts as a collector load for the transistor, eliminating the application of high frequency switching voltages to the ground trace.

Therefore, no high frequency switching voltage is applied to the metal substrate connected to the ground pattern, and switching noise can be prevented from leaking to the outside through stray capacitance caused by the mounting structure of the hybrid integrated circuit device.

Embodiment FIG. 1 shows the circuit configuration of a characteristic active filter employed in the present invention.

This active filter, as shown in the figure,
A bridge rectifier circuit consisting of diodes D1 to D4, which is a feature of the present invention, is a reactor whose one end is connected to the positive DC output end of the bridge rectifier circuit, and whose collector and emitter are respectively connected between the other end of this reactor L and the ground. This transistor Q. The damper diode D5 has an anode connected to the collector of the damper diode D5, a smoothing capacitor C4 is connected between the cathode of the damper diode D5 and the ground, and a control circuit COM supplies a control pulse φ to the base of the transistor Qo.

The main circuit of the control circuit COM is constituted by a microcomputer and outputs a control pulse φ having a frequency of 15 KHz or more. Although not shown, the control circuit COM detects the magnitude of the load current and performs feedback control based on the frequency of the control pulse φ or the duty, and further controls the substrate temperature and the transistor Q.

The emitter current of the active filter is measured to control the active filter so that it does not go out of control thermally.Although a microcomputer was used in the control circuit COM of this embodiment,
It goes without saying that the predetermined control can also be performed using well-known circuit configurations such as comparators and operational amplifiers.

Transistor Q. is not limited to the illustrated bipolar structure transistor, but can be changed to other elements capable of high-speed operation, such as a power MOS transistor, SIT, IGBT, etc. Further, the rectifier circuit is not limited to the illustrated bridge rectifier circuit, and any known type of rectifier circuit can be used.

Next, the operation of the active filter configured as described above will be explained with reference to FIG.

In the half cycle when the potential at the connection point of commercial AC diodes D1 and D2 is positive, 15KH is output from the control circuit COM.
Transistor Q when control pulse φ with a frequency equal to or higher than z is at high level. turns on, diode D1-reactor L-
Transistor Q. - A closed circuit of the diode D4 is formed and a current LL flows through the reactor L. Then, when the control pulse φ is at low level, the transistor Q. When the reactor is turned off and the previously closed circuit is opened, the reactor generates a back electromotive force in an attempt to maintain the previous electrical state. The voltage obtained by adding the back electromotive force of the reactor L and the bridge rectifier circuit output exceeds the charging voltage of the smoothing capacitor C4 for a long period of time compared to a capacitor input type rectifier circuit,
Smoothing capacitor C4 is charged via damper diode D5.

Furthermore, in the half cycle in which the potential at the connection point between the commercial AC diodes D and D2 becomes negative, the transistor Q when the control pulse φ is at a high level. turns on, diode D3-reactor L-) transistor Q. - A closed circuit of diode D2 is formed and a current LL flows through the reactor. Then, the control pulse φ becomes low level and the transistor Q is activated. When is turned off and the previous closed circuit is opened, a back electromotive force is generated in the reactor as before, and the smoothing capacitor c6 is charged by the voltage obtained by adding the back electromotive force and the output of the bridge rectifier circuit.

This will be explained in more detail with reference to FIGS. 3(A) and 3(B).

FIG. 3(A) shows an equivalent circuit of the hybrid integrated circuit device in a half cycle in which the potential at the connection point between the commercial AC diodes D and D2 becomes positive. In this positive half cycle, diode D1-reactor L-) transistor Q. -Diode D
4 forms a closed circuit, and the reactor L is the transistor Q. It is located at a position where it is a collector load.

On the other hand, Fig. 3 (B) shows the commercial AC diode D.
1 shows an equivalent circuit of the hybrid integrated circuit device in a half cycle in which the potential at the connection point between 1 and D2 becomes negative. In the negative half cycle, diode D2 - reactor L - transistor Q. - A closed circuit is formed by the diode D3, and the reactor is connected to the transistor Q as in the positive half cycle. This is a collector load.

Therefore, according to the circuit configuration of this active filter, the transistor Q is always a reactor in both the positive half cycle and the negative half cycle of the commercial AC. Since it is inserted on the collector side of the transistor Q. The emitter potential of is always stable at ground potential.

Referring to FIG. 4, a specific structure of an embodiment in which the above-described active filter is mounted on an insulated metal substrate except for the reactor and smoothing capacitor C4 will be described.

The circuit pattern with diagonal lines is the ground pattern, and the circuit board has a part of the ground pattern.
It is divided into two parts: a small signal circuit block corresponding to the blank area in the upper half of the drawing, and a large current circuit block corresponding to the lower half of the drawing. In this embodiment, the circuit is supplied from the small signal circuit block to the large current circuit block. Wiring of control pulse φ or transistor Q supplied from large current circuit block to small signal circuit block. The emitter potential wiring is formed so as to bypass a part of the ground pattern, but is not limited to this, for example, the emitter potential wiring of the transistor Q. The emitter potential wiring may be connected to a predetermined position of the small signal block by a bonding wire (jumping wire connection).

Furthermore, this ground pattern is a transistor Q through which high frequencies and large currents flow. It is connected to the aluminum substrate by a bonding wire W at a position closest to the emitter of the aluminum substrate to make the aluminum substrate potential equal to the ground pattern potential.

In the large current circuit block, diodes D1 to D4, a damper diode D5, and a transistor Q0 forming a bridge rectifier circuit are surface mounted via a heat sink, and a transistor Q is also mounted on the surface of the large current circuit block. An emitter resistor R is formed to limit the emitter current of and measure its value. These elements are arranged so that a large current does not flow into the ground pattern portion that divides the small signal circuit block and the large current circuit block. The external lead terminals that connect the large current circuit block and the external circuit and the external lead terminals of the small signal block are arranged on opposite peripheral edges of the circuit board so that they are loosely coupled to each other.

In addition, since the distance between the externally connected smoothing capacitor cd and the damper diode D5 greatly affects the charging and discharging ability of the smoothing capacitor cd, the damper diode D is placed close to the terminal indicated by V in Figure 4. be done. Furthermore, for the same reason, the terminal indicated by ``■'' and the ground terminal GND are arranged adjacent to each other.

Note that the cross-sectional structure of the hybrid integrated circuit device shown in FIG. 4 is the same as that in FIG. 7, so a description thereof will be omitted.

The above-described hybrid integrated circuit device of the present invention is mounted on the chassis of an electronic device by bringing the back surface of the insulating metal substrate into contact with the chassis of the electronic device, taking heat dissipation into consideration. Therefore, a stray capacitance CP is interposed between the metal substrate of the insulated metal substrate and the chassis as shown in FIG. 3. However, since the metal substrate is connected to the ground pattern (the shaded area in FIG. 4) by the bonding wire W, the potential becomes the same as that of the ground pattern.

According to the invention, the ground pattern, i.e. transistor Q. Since the emitter potential of C3 is stable at the ground potential as described above, there is no possibility that switching noise will flow into the chassis during the negative half cycle of the commercial AC via this stray capacitance C3.

FIG. 5 shows a circuit diagram of a modification of the embodiment.

The control circuit COM of the above embodiment has a function of outputting multiphase pulses for controlling the inverter circuit, and outputs the multiphase pulses from the hybrid integrated circuit device to the outside. Although such a hybrid integrated circuit device has the advantage that it can be constructed on a relatively small scale, it has the disadvantage that it requires a large number of terminals for externally outputting multiphase pulses.

On the other hand, in a modified example, a three-phase inverter circuit composed of transistors Q1 to Q6 is also mounted on a single circuit board, and the control circuit COM is connected to the transistors Q, through a circuit pattern formed on the circuit board. Multiphase pulses are manually applied to the base of Q6.

This reduces the number of terminals and prevents noise from entering the wiring between the active filter and the inverter circuit.

(G) Effects of the Invention As described above, according to the hybrid integrated circuit device of the present invention, (1) Since the potential of the emitter of the transistor of the active filter is at ground potential at high frequencies, the metal substrate of the hybrid integrated circuit device There is no fear of switching noise leaking from the electronic device to the chassis of the electronic device, and a hybrid integrated circuit device equipped with an extremely small active filter can be realized.

(2) Since the large current circuit and the control circuit are separated by a ground pattern, the control circuit is shielded from noise generated in the large current circuit.

(3) Since the inter-element wiring constituting the active filter becomes shorter due to the use of a hybrid integrated circuit device, noise caused by wiring inductance is suppressed.

(4) Since an insulated metal substrate is used as the circuit board, a relatively large stray capacitance is formed between the wiring pattern and the metal substrate, and harmonic noise can be quickly attenuated in the vicinity of the point where it occurs.

(5) Since an insulated metal substrate is used as the circuit board, heat dissipation characteristics are good, and the active filter can be made compact.

(6) Since an insulated metal substrate is used as the circuit board, unnecessary radiation from the hybrid integrated circuit device to the outside can be suppressed.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram explaining the active filter adopted in the present invention, Fig. 2 is an operation waveform diagram of the active filter, and Fig. 3 (A) and (B) explain changes in emitter potential of the transistor of the present invention. 4 is a plan view of the embodiment, FIG. 5 is a circuit diagram of a modified example, and FIG. 6 is an active circuit diagram of a conventional example.
The circuit diagram of the filter, FIG. 7 is a cross-sectional view of the circuit board, and FIG. 8 (A>(B) is a diagram explaining the emitter potential change of a conventional transistor, each representing the equivalent of each half cycle of commercial AC. It is a circuit diagram. L...reactor, D1-D5...diode, c
d...Smoothing capacitor, Q...Transistor, C
OM...control circuit.

Claims (5)

[Claims] (1) On the circuit pattern of the insulated metal board,
In a hybrid integrated circuit device that includes at least a rectifier circuit that constitutes a filter, a switching element, and a diode that extracts charging voltage from the switching element, a reactor is connected between the DC output terminal of the rectifier circuit and the switching element, and the output of the diode is A hybrid integrated circuit device, characterized in that a charging capacitor is connected to the side thereof, and a connection part is provided for connecting a ground pattern of a circuit pattern and a metal substrate. (2) The hybrid integrated circuit device according to claim 1, wherein the insulating metal substrate is coated with an oxide film formed by anodizing the surface of an aluminum substrate. (3) The hybrid integrated circuit device according to claim 1, wherein the rectifier circuit is a bridge rectifier circuit. (4) The hybrid integrated circuit device according to claim 1, wherein the switching element is composed of a bipolar transistor, a MOS transistor, an SIT, or an IGBT. (5) The hybrid integrated circuit device according to claim 1, wherein the connection portion is formed of a bonding wire.